JPS59219319A - Unsaturated polyester resin composition - Google Patents

Abstract

PURPOSE:The titled resin composition which, when applied to an adherend, can cure without heating and gives a protective film thereto, obtained by mixing an unsaturated polyester with a vinyl monomer having a nitrogen atom-containing heterocyclic ring as a substituent. CONSTITUTION:An unsaturated polyester is prepared by reacting an acid component comprising 20-80mol% 4C or higher aliphatic unsaturated polybasic acid, e.g., fumaric acid, and 80mol% or below 4C or higher aliphatic saturated acid, e.g., succinic acid, or alicyclic polybasic acid, e.g., tetrahydrophthalic anhydride, with an alcohol component containing 50mol% or above polyhydric alcohol having a branched carbon chain, e.g., propylene glycol. This unsaturated polyester is mixed with a vinyl monomer having a substituent which is five- or six-membered heterocyclic ring containing one or two nitrogen atoms, e.g., 2- vinylpyridien or N-vinylpyrrolidone, to form the titled resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to unsaturated polyester resin compositions. The unsaturated polyester 40.1 fat composition of the present invention is useful as a pressure-sensitive adhesive for protective films.

The protective adhesive sheet is applied to products that require surface protection, such as decorative plywood, acrylic boards, stainless steel boards, glass boards, etc., to prevent damage during cutting or transportation of these products.

This is an adhesive sheet for surface protection whose main purpose is to prevent discoloration and deterioration during long-term storage.

In recent years, its uses have been expanding. Therefore.

The basic performance required of adhesive sheets for protection is that the adhesive does not transfer to the surface of the product during processing or storage, and that when it is peeled off, there will be no adhesive residue or cloudy phenomenon, and that it will not cause adhesive residue or clouding, and that it should not cause adhesive residue or clouding when it is peeled off. Because it is often applied to articles with complex surfaces, it must maintain appropriate adhesion and sufficient flexibility.

Description of the Prior Art Conventionally, protective adhesive sheets have been made mainly of acrylic polymers, rubber polymers, or ethylene-vinyl acetate polymers, and if necessary, additives such as tackifying resins and plasticizers have been added to them by organic dissolution or I. It is manufactured by applying the dispersed /i1 onto a support such as Phil 211 paper and cloth, and then heating and drying it.

Conventional protective pressure-sensitive adhesive sheets made in this manner are suitable for protecting the surface of an adherend for a long period of time.

The additive migrates to the surface of the adherend, and when the adhesive sheet is peeled off, adhesive residue and clouding occur, 81! This could significantly reduce the product value. In addition, all conventional methods involve a heating process, which not only consumes a large amount of thermal energy, but also poses problems such as limitations on the types of supports and additives, and the need to enlarge the production line. Therefore, there has been a demand in the optical industry for a protective adhesive sheet that can be applied and cured without heating and has excellent long-term protection performance for various types of decorative plywood.

As a method of curing liquid resin at room temperature, there is generally a method of irradiating a resin that can be cured by a radical chain mechanism with frost ((sexual radiation, especially %), and irradiation with heat. Unsaturated polyester resin is a typical liquid resin, but the cured product of this resin is generally characterized by extremely rigid physical properties, so it has not been used conventionally in glass fiber reinforced plastics (FRP) or paints. The present inventors have conducted intensive research contrary to common knowledge regarding conventional unsaturated polyester resins, and have already developed a resin composition that exhibits 1-strong adhesion by curing with electron and electron beams. (Japanese Patent Application No. 55-72451), but as a result of repeated research, we have developed a specific vinyl monomer of unsaturated polyester, which is described in detail below. The present inventors have discovered that by curing an unsaturated polyester resin composition consisting of the following, it is possible to form a protective adhesive sheet with excellent long-term protection performance for various objects to be protected, and have thus arrived at the present invention.

Therefore, in order to solve these problems, the purpose of the present invention is to provide a protective adhesive that can be applied without heating, applied directly to the adherend, and cured to have excellent long-term protection performance for various objects to be protected. The object of the present invention is to provide a solvent-free liquid unsaturated polyester resin composition suitable for sheets.

A further object of the invention is an unsaturated polyester.

To provide an unsaturated polyester cinnamon fat composition 7 useful as an adhesive for a protective film, which is mainly composed of a vinyl monomer having a 5- or 6-membered heterocycle having 11:c to 2 nitrogen atoms as a substituent. It is.

Furthermore, another object of the present invention is to apply the unsaturated polyester resin composition of the present invention to the surface of an adherend without heating. It is an object of the present invention to provide a method for forming a protective film.

Other objects and advantages of the invention will be highlighted below.

One component of the unsaturated polyester resin composition of the present invention is mainly composed of a specific acid component and a specific alcohol component, the unsaturated polyester thus produced, and a specific vinyl monomer. The unsaturated polyester is an aliphatic unsaturated polybasic acid having 4 or more carbon atoms with 20 to 80 moles of carbon atoms (an aliphatic saturated polybasic acid or aliphatic acid having 4 or more carbon atoms). A polyhydric alcohol having one or more carbon branch chains as an alcohol component, using at least one type of cyclic multi-IRffi base acid in an amount of 80 mmol below the acid component.
It is produced by polycondensation by heating using 50 molar or more.

The aliphatic unsaturated polybasic acids used in the present invention have four or more carbon atoms, and are preferably exemplified by maleic anhydride, fumaric acid, itaconic acid, citraconic acid, and the like. These aliphatic unsaturated polybasic acids are used singly or as a mixture of two or more in an amount of 20 to 80 mol of the acid component. In addition, examples of aliphatic f--wa polybasic acids include succinic anhydride, succinic acid, adipic acid, azelaic acid, sebacic acid, etc., and examples of aliphatic JR type polybasic acids include tetrahydrophthalic anhydride, cis-4 -cyclohexane 1,2-
Dicarboxylic anhydride, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, tetrapropenylsuccinic anhydride, etc.5 are exemplified, and one or two of these 5
Mixtures of more than one species can be used in any effective range not exceeding 80 mole percent of the acid component.

Also, the carbon branched chain used in the present invention? Polypropylene alcohol (propylene glycol).

diglopidine glycol, 1,5-phthanediol.

1.4-hair diol, 2-ethylhexane 1°6
-diol, 2,2-dimethylpropane-1,5-diol, and 2,2.4-1rimedylpebutane-1,6-diol. f11! Alternatively, a mixture of two or more types may be used with an alcohol content of 50 moles or more.

Also, linear polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, and 1,4-butanediol? The alcohol component can be used in an amount not exceeding 50 moles.

An unsaturated polyester is produced by mixing the above components and subjecting them to polycondensation using a conventional method. The molecular weight does not need to be particularly limited, but it is suitably in the range of i,ooo to 10,000 in order to achieve compatibility with the monomers used or a viscosity that facilitates coating.

The vinyl compound having a 5- or 6-membered heterocyclic ring containing 1 or 2 nitrogen atoms, which is one component of the composition of the present invention, is 2-vinylpyridine.

N-hinylcarhasol, N-vinylpyrrolidone, 6-
Examples include vinyl indole and N-vinylimidazole. What are the amounts of these monomers used?

It is preferably 0.1 to 15 moles, <Hao, 2 to 10 moles, based on the unsaturated bonds contained in the unsaturated polyester.

The unsaturated polyester resin composition of the present invention is produced by mixing and dissolving the liquid vinyl monomer described above in the unsaturated polyester, which is one of the components of the present invention described above. At this time, the blending ratio of both components is 0.00% of the unsaturated bonds contained in the unsaturated polyester.
A range of 1 to 15 molar equivalents is preferred.

The unsaturated polyester resin composition of the present invention is used as an adhesive for a protective film. Therefore, if it is necessary to adjust the protection performance depending on the type of adherend, other radically polymerizable vinyl monomers may be mixed and dissolved in an effective amount of 30 parts by weight or less based on the total monomer amount. .

What are other radically polymerizable vinyl monomers?

General formula % Formula % (I (1 is H or C)]2; R2 has 2 to 1 carbon atoms
Examples include acrylic ester monomers represented by (5 alkyl groups), styrene, divinylbenzene vinyl acetate, and the like.

Furthermore, additives (materials) known in the art, such as fillers such as calcium carbon and titanium oxide and/or anti-aging agents, may be added to the unsaturated polyester resin composition of the present invention, if necessary. can. However, a major feature of the present invention is that it does not require additives such as tackifying resins and plasticizers that are commonly used.

The method of curing the liquid unsaturated polyester resin composition of the present invention to produce a pressure-sensitive adhesive sheet for a protection film includes a conventional method of adding a known radical generator and heating, or a method of adding a photosensitizer and irradiating with ultraviolet rays. However, from the perspective of the purpose of the present invention, the most suitable method is to irradiate with ionizing radiation, particularly electron beams generated by an electron beam accelerator. The irradiation atmosphere may be air, but preferably an inert gas atmosphere. Also.

The energy for electronic recording does not need to be particularly limited, but the acceleration voltage is 150 KeV to 50 D KeV from the viewpoint of resin thickness or production speed in manufacturing the protective adhesive sheet.
A certain degree is efficient.

The support for curing and curing the liquid resin composition of the present invention may be a plastic film, paper,
Various materials such as cloth can be used. In conventional methods, when a polyethylene or polypropylene film is used as a support, corona discharge treatment or coating treatment with a surface treatment agent is usually performed to improve adhesion with the resin. Pretreatment is not necessarily required. This is also one of the features of the present invention.

Further, as a method for applying the liquid resin composition of the present invention to these supports, a conventional method for applying a solvent-based resin can be used as is.

The protective adhesive sheet obtained from the unsaturated polyester resin composition of the present invention by the method described above retains good flexibility and has excellent long-term accelerating performance for decorative plywood.

In order to explain the present invention in more detail, Examples and Comparative Examples are shown below, but the content of the present invention is not limited to the Examples.

Example 1 4 moles of fumaric acid, 6 moles N of sebacic acid, 2,2.4-) lamethylbentane 1. '5-Diol 11 was condensed by heating for 1.5 hours (maximum temperature: about 220°C) while stirring in a gas atmosphere to obtain unsaturated polyester A with an acid value of 28. The average molecular weight of this unsaturated polyester A is 3/DO
(Based on gel permeation chromatography using a polystyrene standard sample). Next, this unsaturated polyester A100y-, 0.6 mol of various IIC monomers? We created resins that were understood to be different from each other. These resins were coated on a polyethylene film with a thickness of 40 μm at #'
10S'/n? It was applied using an applicator so that

Each sample was irradiated with a 500 keV electron beam generated from a transformer rectified accelerator in a nitrogen stream using a conveyor system. hardened. Table 1 shows the results of measuring the protection performance of the cured sheet. In addition.

The protection properties were evaluated by cutting the cured sheet into 10cm x 15m test pieces and attaching them to a lined glass plate at 25°C.
．． After standing in an environment of 65% RH for 7 days, the sample piece was peeled off, and the resistance to peeling and the glass surface were visually observed.

As is clear from the results in Table 1.0, even if styrene and methyl methacrylate, which are commonly used in unsaturated polyester resins, are used, the resin migrates to the glass surface instead of forming lumps with low adhesive strength, resulting in poor protection performance. . Furthermore, although loop tyl acrylate and 2-ethylhexyl acrylate have good viscosity, resin still remains on the glass surface, making them unsuitable as protective adhesives. On the other hand, when the nitrogen atom-containing heterocyclic vinyl monomer of the present invention, ie, N-vinylpyridine or N-vinylpyrrolidone, is blended, a pressure-sensitive adhesive sheet with good peel resistance and protection performance from the glass surface condition can be obtained.

Examples 2-5, Comparative Examples 1-6 Table 2. With the combination of dibasic acid and polyhydric alcohol shown in Example 1. In the same manner as above, unsaturated polyesters B, C, I), E, Ii', G, )l were prepared.

Each of these unsaturated polyesters contains 10 (0.
Mix and dissolve 5 mol of N-vinylpyrrolidone, Example 1
Samples were prepared and irradiated with electron beam in the same manner as in , and the protection performance of the cured sheet was evaluated. The results are shown in Table 6. Shown below. In the table, enriched physical properties are when the test piece is stored for a specified period of time in an environment of 26°C, 160% H, The samples were immediately moved to an environment of 26° C. and 60% RH, left for 5 hours, and then measured.

From the results in Table 6.0, Example 2 corresponding to the composition of the present invention
The pressure-sensitive adhesive sheet No.-5 provides excellent protection properties in both normal and accelerated physical properties. Cloudiness and residual resin were also observed in cases where the amount of unsaturated polybasic acid was small) and Comparative Example 6 (when aromatic polybasic acid was used without using aliphatic saturated polybasic acid). , it is unsuitable as a protective adhesive sheet.

Examples 6 to 8, Comparative Example 4.5 A resin liquid having the composition shown in Table 4 was prepared for the unsaturated polyester D shown in Table 2, and samples were prepared and electron beam irradiated in the same manner as in Example 1. The protection performance (normal condition for 7 days) of the cured product was measured in the same manner as in Example 2. The results are shown in Table 5. As is clear from Table 5, in the adhesive sheets of Examples 6 to 8 corresponding to the composition of the present invention, the glass plate,
Excellent protection performance was obtained for both acrylic and aluminum plates. On the other hand, comparative example 4
In both Comparative Example 5 (when the amount of monomers added is too large) and Comparative Example 5 (when the amount of monomers other than the polycyclic vinyl monomer is too large), migration of the resin was observed on the surface of the protected object, and the protection performance decreased. It was defective.

Table 4゜Resin monomer blending amount Acrylic acid 1゜Dodecyl methacrylate 1゜D-4N-vinylpyrrolidone 8゜Styrene
20

Claims (1)

[Claims] 1. Unsaturated polyester and 1 or 2 nitrogen atoms
An unsaturated polyester resin composition mainly consisting of at least one vinyl monomer having as a 5- or 6-membered double-bed ring substituent. 2. The composition according to claim 1, wherein the vinyl monomer is used in an amount of 0.1 to 15 moles based on the unsaturated bonds contained in the unsaturated polyester. 6. The composition according to claim 1, wherein the vinyl monomer is used in an amount of 0.2 to 10 moles based on the unsaturated bonds contained in the unsaturated polyester. 4. The composition according to claim 1, wherein the unsaturated polyester has molecules ii1 in the range of 1000 to 10,000. 5. The unsaturated polyester contains a 20 to 80 molar component of an aliphatic unsaturated polybasic acid having 4 or more carbon atoms, and an aliphatic saturated polybasic acid or alicyclic polybasic acid having 4 or more carbon atoms. Claim 1 prepared by using at least one effective amount of an acid component of not more than 80 moles and a polyhydric alcohol having at least one carbon branch chain and an alcohol component of not more than 50 moles. Compositions as described in Section. 6. General formula (where R1 is H or CH3; R2 is a carbon atom of 2 to
2. The composition according to claim 1, which contains a radically polymerizable vinyl monomer represented by 15 alkyl groups in an effective amount of 30 parts by weight or less based on the total amount of monomers.